From patchwork Wed Jul 13 19:08:45 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Anna Schumaker X-Patchwork-Id: 12917035 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 064A5C433EF for ; Wed, 13 Jul 2022 19:09:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236850AbiGMTJA (ORCPT ); Wed, 13 Jul 2022 15:09:00 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34924 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236885AbiGMTIz (ORCPT ); Wed, 13 Jul 2022 15:08:55 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 736091EC5F for ; Wed, 13 Jul 2022 12:08:54 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 2F7D5B82130 for ; Wed, 13 Jul 2022 19:08:53 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8CD55C341C0; Wed, 13 Jul 2022 19:08:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1657739331; bh=MoEnAgAkrZFeK8lW3w10TAccR4+ENUqcgZQSw8DGZIc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=p1Lj2KxcAt9gn4C3dOx9zs7UF5n6mhZGJ80iA85/zacewAp65T5lkSnnTaqpnBeK9 6pK6B0GmQy4TpZ6z9HfGOcFx+wW4R7LAzcVU8hwE6ldOb6YxT89pcwO7xje+8FLQtD ed9N/98YrwjeSwFQLXyWFC2ilJYw/aSslmDB596ZqRxe6709TFpwr+aNYlk07nnlYn e72iZmNLinJHHMtvE8eG3Tm2MjYX1lwqJQfqcwbJ3wEu5WZgj/POaXMNZXfHZD2dqd wERqgsEfpE+QNzes9juqC0At9DA1FXAZKZ0A59Xs+R0+cum8TsnS3PbJcRwBtlbX4o i/HH3QsPcqttg== From: Anna Schumaker To: linux-nfs@vger.kernel.org, trond.myklebust@hammerspace.com Cc: anna@kernel.org Subject: [PATCH v2 1/5] SUNRPC: Add a function for directly setting the xdr page len Date: Wed, 13 Jul 2022 15:08:45 -0400 Message-Id: <20220713190849.615778-2-anna@kernel.org> X-Mailer: git-send-email 2.37.0 In-Reply-To: <20220713190849.615778-1-anna@kernel.org> References: <20220713190849.615778-1-anna@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org From: Anna Schumaker We need to do this step during READ_PLUS decoding so that we know pages are the right length and any extra data has been preserved in the tail. Signed-off-by: Anna Schumaker --- include/linux/sunrpc/xdr.h | 1 + net/sunrpc/xdr.c | 30 ++++++++++++++++++++++++++++++ 2 files changed, 31 insertions(+) diff --git a/include/linux/sunrpc/xdr.h b/include/linux/sunrpc/xdr.h index 79824fea4529..b8f3011e109b 100644 --- a/include/linux/sunrpc/xdr.h +++ b/include/linux/sunrpc/xdr.h @@ -262,6 +262,7 @@ extern __be32 *xdr_inline_decode(struct xdr_stream *xdr, size_t nbytes); extern unsigned int xdr_read_pages(struct xdr_stream *xdr, unsigned int len); extern void xdr_enter_page(struct xdr_stream *xdr, unsigned int len); extern int xdr_process_buf(const struct xdr_buf *buf, unsigned int offset, unsigned int len, int (*actor)(struct scatterlist *, void *), void *data); +extern void xdr_set_pagelen(struct xdr_stream *, unsigned int len); extern unsigned int xdr_align_data(struct xdr_stream *, unsigned int offset, unsigned int length); extern unsigned int xdr_expand_hole(struct xdr_stream *, unsigned int offset, unsigned int length); extern bool xdr_stream_subsegment(struct xdr_stream *xdr, struct xdr_buf *subbuf, diff --git a/net/sunrpc/xdr.c b/net/sunrpc/xdr.c index ea734b14af0f..9d7c93645f01 100644 --- a/net/sunrpc/xdr.c +++ b/net/sunrpc/xdr.c @@ -1518,6 +1518,36 @@ unsigned int xdr_read_pages(struct xdr_stream *xdr, unsigned int len) } EXPORT_SYMBOL_GPL(xdr_read_pages); +/** + * xdr_set_pagelen - Sets the length of the XDR pages + * @xdr: pointer to xdr_stream struct + * @len: new length of the XDR page data + * + * Either grows or shrinks the length of the xdr pages by setting pagelen to + * @len bytes. When shrinking, any extra data is moved into buf->tail, whereas + * when growing any data beyond the current pointer is moved into the tail. + * + * Returns True if the operation was successful, and False otherwise. + */ +void xdr_set_pagelen(struct xdr_stream *xdr, unsigned int len) +{ + struct xdr_buf *buf = xdr->buf; + size_t remaining = xdr_stream_remaining(xdr); + size_t base = 0; + + if (len < buf->page_len) { + base = buf->page_len - len; + xdr_shrink_pagelen(buf, len); + } else { + xdr_buf_head_shift_right(buf, xdr_stream_pos(xdr), + buf->page_len, remaining); + if (len > buf->page_len) + xdr_buf_try_expand(buf, len - buf->page_len); + } + xdr_set_tail_base(xdr, base, remaining); +} +EXPORT_SYMBOL_GPL(xdr_set_pagelen); + unsigned int xdr_align_data(struct xdr_stream *xdr, unsigned int offset, unsigned int length) {